Underfeed stoker



Aug. 23,1927. 1,640,164

W. F. TROTTER 'UND ERFEED STOKER l d Dec. 19; 1921 5 Sheets-Sheet 1 I l O 5% WWMW?-W Aug. 23, 1927. 1,640,164

w. F. TROTTER UNDERFEED STOKE-R Filed Dec. 19. 1921 5 Sheets-Sheet 2 HQ, v

' WWw'w-w 1927' F. TROTTER UNDERFEED STOKER 7 Filed Dec. 19. 1921 s Shets-Sheet 3 MWWWNWR Aug. 23 l w. F. TROTTER UNDERFEED STOKER Filed Dec. 19, 1921 5 Sheets-Sheet 4 ww wmm atto'muuf W. F. TROTTER UNDERF'EED STOKER Aug 23, 1921. 1,640,164

Filed Dec. 1921 5 Sheets-Shet 5 Patented Aug. 23, 1927.

UNITED STATES 1,640,164 PATENT OFFICE.

WALTER F. TROTTER, OF CINCINNATI, OHIO, ASSIGNOR TO DETROIT STOKER COM- PANY, OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN.

UN DERFEED STOKER.

Application filed December 19, 1921. Serial No. 523,251.

burning fuel and is gradually elevated into I the zone of combustion. The invention consists primarily invarious structural features of the furnace bed plates and the tuyere blocks and in a novel relation between said plates and blocks.

In the drawings Figure 1 is a plan stoker;

Figure 2 is a cross section view of the same taken on line 2-2 of Figure 1;

Figure 3 is a vertical sectional detail on line 3-3 of Figure 1 showing one of the rear end tuyere blocks;

Figure 4 is a perspective detail of one of the bed plates;

Figure 5 is a perspective detail of an inverted tuyere block; I

Figure 6 is a cross section view of the same;

Figure 7 is a fragmentary plan view of the front tuyere block and a portion of the retort, supporting said block;

Figure 8 is a rear elevationview of said block with certain parts in section; 4

Figure 9 is a view of said block and associated structure in cross section;

Figure 10 is a fragmentary longitudinal sectional view of the stoker.

In these views the reference characters 1 and 2 respectively designate the front and rear walls of a furnace and 3 a trough shaped retort into which the green fuel is fed and which passes through and extends rearwardly from the front wall of the furnace. 4 is a push rod operating within said retort to assist feeding of the fuel. Upon each edge of said retort there rest the upper ends ofa row of closely adjoining inclined bed plates 5, the lower ends of each row being supported in common upon a sill formed by a beam 6. Said beam is flanged as indicated at 6 and the bed plates 5 are formed with integral depending hooks 6 engaging the flanges 6' Upon the upper end portion of each plate 5 there is mounted one or more detachable tuyere blocks 7. Said blocks are each formed with a pair of holding lugs 8, downwardly projecting into openings 9 formed in the horizontal upper end portions of the bed plates. A red 10 formsa common means for securing view of the improved all the aligned tuyere blocks to the corresponding bed plates and for securing said bed plates to one another, said rod being passed through registering apertures in the lugs 8 and in ribs 10 depending from the plates 5. The rods 10 project slidably through the front wall 1 of the furnace so as to be readily accessible. By withdrawing said rods to a greater or less extent any of the tuyere blocks or bed plates can be removed from its position of use. The inclined top surface of each plate 5 is transversely shouldered as indicated at 11 at a suitable intermediate point preferably relatively near the tuyere blocks. The inclined top faces of said plates 5 are ribbed as indicated at 12 to form shallow pockets 12 both above and below the shoulder 11. Said pockets serve to retain a layer of fine ash which acts as a heat insulation to protect the plates from the intense heat given out by the mass of fuel supported by said plates. Recesses 13 formed in the tops of the tuyere blocks serve a similar purpose. 1 1 designates dump plates, a row of which is arranged at each side of the furnace bed. Each row of plates 14 is mounted fast upon a rock shaft 15 extending through the front wall of the furnace and adapted to swing said plates'down when desired to permit the plates to discharge their load into the ash pits 15; 16 is an air chamber formed beneath the plates 5 and about the retort 3, air under pressure being delivered to said chamber from any suitable source, as is common practice. Each of the tuyere blocks 7 is formed with an air passage 17 having an inlet in the bottom of said block communicating with the chamber 16. As shown the majority of the blocks 7 have one side wall thereof formed with a plurality of air outlets 18 for discharging air above the retort, while each opposite side wall is provided with a single outlet 18" for discharging air in the direction of inclination of the plates 5. The number of air outlets may be varied in different blocks according to the fuel conditions normally prevailing adjacent said blocks. It is preferred to form the blocks 7 with internal ribs 19 just below the outlets 18 and 18 as a preventive against ashes entering the tuyere blocks through said outlets and also to assist in giving discharging air a strictly lateral direction. Preferably the ribs are turned aeeaiee slightly upward at their free edges as is best seen in Figure 6.

21 designates a tuyere block of special form which is set into the front wall 1 of the furnace, said block bridging the retort 3 and being formed with legs 22 respective- 1y seating upon the edges of said retort as is best seen in Figure 8. Said legs are tern'iinally formed with lugs 23 which fit into grooves 24 in the edges of the retort to assist in properly positioning the tuyere block. Also a lug 24 projects forwardly from the block 21, engaging normally in a slotted keeper Ql integrally upstanding upon the inverted channel shaped plate 24 which bridges the retort beneath the front wall 1. The lugs 23 and 24 assist in properly positioning the block 21, and the grooves 524 permit said blocks to be slid rearwardly if it becomes necessary to remove said block from its normal location in the wall 1. The legs 22 are hollow, forming air passages 25 into which air may rise from the chamber 16 and be delivered to the hollow upper portion of the DlOCk, from which the air may discharge rearwardly through a plurality of outlets 26 having a suitable elevation above the retort. The air thus discharging supports combustion of such gases as may be given off by the fuel upon its initial introduction into the furnace, said gases rising in proximity to the front wall 1.

28 designates a pair of tuyere blocks arranged in proximity to the rear furnace'wall 2, said blocks having portions aligned with the row of blocks 7 and having portions projecting toward each other and substantially abutting. The blocks 28 are preferably provided with L-shaped portions 28' which seat partially upon the adjacent plates 5 and partially upon a fiat rear end portion 30 of the retort. Said blocks are supplied with air from the chamber 16 both through openings 9 such as have been described and through openings 31 forming in the retort .extremity 30. 32 designates inclined faces of the blocks 28 which constitute an upward extension of the inclined rear end face 33 of the retort. 34 are air ports discharging forwardly through the inclined faces 32.

In the operation of the described invention, the fuel graduallv discharging from the retort 3 feeds laterally in each direction passing over the row of tuyere blocks 7 and feeding down the incline of the bed plates 5. The mass of fuel is subjected to a. sudden drop in passing from above the tuyere blocks to the relatively low inclined faces of the plates 5 and a similar drop occurs when the shoulder 11 is encountered by the fuel, the effect being to break up the masses of fuel and secure a more thorough combustion thereof. If for any reason it becomes necessary to inspect or replace any of the bed plates or tuyere blocks the described construction permits a ready removal of such parts. The supply of air delivered to the fuel by the tuyere blocks may be quite accurately predetermined according to the normal condition of the fuel in various parts of the furnace by varying the number of outlets in the tuyere blocks at different points. Thus it will be observed that the blocks 7 nearest adjacent the front wall 1 are blank as regards outlets opening above the plates 5 and have each only one outlet dischargin above the retort. The next adjacent bloc s have each only one outlet discharging above the bed plates and two outlets discharging above the retort, while each of the remaining blocks has two outlets discharging above the bed plates and four outlets discharging above the retort. The inclined faces 32 of the rear blocks 28 cooperate with the inclined rear end 33 of the retort in causing the fuel to rise from the redischarge of air into the mass of fuel adjacent the rear wall.

An advantageous feature of the described construction is the detachable seating of the tuyere blocks upon the bed plates. Thus, not only said blocks but the elements which provide seats for the blocks are independently removable, so that the expense involved in replacing any block or its seat forming plate is minimized.

While the construction illustrated and de scribed is of the side dumping type it will be readily understood that certain features of the invention are equally applicable to an end dumping construction.

What I claim as my invention is 1. In a furnace bed, an inclined plate transversely shouldered intermediately of its upper and lower ends to effect a drop of fuel, feeding down the incline, for the purpose of breaking up said fuel, said plate having its top surface formed with pockets above and below said shoulder to retain heat comprising a row of inclined plates, of'

tuyere blocks respectively surmounting the upper end portions of said plates and a common means for securing said blocks to said plates. and said plates to each other.

3. The combination'with a furnace bed, comprising a row. of inclined plates, of tuyere blocks respectively. surmounting the upper end portions of said plates, and a pin extending exteriorly of the furnace, detachably securing said blocks upon said plates and said plates to each other.

4. The combination with a trough-shaped retort, and a wall at one end of said retort, of a tuyereblock set into said Wall, bridging the retort and having hollow legs seating upon the edges of the retort and depending lugs respectively formed on said legs, the

edges of the retort having grooves engaged by said lugs elongated to permit removal of the tuyere block from the wall.

5. In a furnace bed, a series of bed plates, each bed plate having a horizontal portion and an inclined portion, the horizontal portion of each bed plate having an opening therein, tuyeres mounted on the horizontal portions of said bed plates and having lugs engaging the openings therein, ribs depending from the bed plates, and a member engaging said ribs and lugs for securing all of said tuyeres to the corresponding bed plates and for securing said bed plates to each other.

6-. In a furnace bed, the combination with an elongated bed plate extending between the tuyere and dump plate of the furnace and having an inclined portion, a horizontal portion at the upper end of the inclined portion, and a transversely shouldered portion intermediate the inclined and horizontal portions, said horizontal portion having a vertical opening therein for the passage of air, of a hollow tuyere mounted on the horizontal portion of the bed plate having an air inlet opening at the bottom engaging with the opening in the bed plate and having an air outlet opening in the wall thereof above the transversely shouldered portion of the bed plate, and means for positioning said tuyere on said bed plate including a lug extending downwardly from a wall of the tuyere engaging a wall of the opening in the horizontal'portiori of the bed plate.

7 In a furnace, the combination with a wall thereof, of a trough-shaped retort having grooves at the opposite sides thereof, an inverted channel-shaped plate extending longitudinally of the retort beneath a portion of the Wall aforesaid of the furnace, an apertured lug carried by the plate, an inverted substantially U-shaped hollow tuyere bridging the retort at one end of the plate, said tuyere having air inlet openings at the lower ends of the hollow leg portions thereof, and an air outlet opening in the intermediate horizontal portion thereof, the lower wall of the horizontal portion of said tuyere being in substantial alignment with the top of said channel-shaped plate, and means for positioning said tuyere including 8. lug projecting from the horizontal portion thereof engaging the apertured lug of the plate, and lugs projecting from the leg portions thereof engaging the grooves in the sides of the retort.

8. In a furnace, the combination with a wall thereof, of a trough-shaped retort, an

inverted channel-shaped plate extending longitudinally of the retort beneath a portion of the wall aforesaid of the furnace, an inverted substantially U-shaped hollow tuyere bridging the retort and overlying the plate at one end thereof, said tuyere having air inlet openings at the lower ends'of the hollow leg portions thereof, and an air outlet opening in the intermediate horizontal portion thereof, the lower wall of the horizontal portion of said tuyere being in substantial alignment. with the top of said channelshaped plate, and means secured to the tuyere and engaging said plate for removably positioning said t-uyere.

9. In a furnace bed, a hollow tuyere having an air inlet opening at the bottom thereof. and air outlet openings in certain of the side walls thereof, the top of said tuyere being entirely closed and having a substantially V-shaped depressed portion to retain heat insulating material, the sides of the V- shaped portionmerging into the apertured sides of the tuyere at the upper edges of the openings, whereby the air will be directed and oppositely deflected by the V-shaped portion through the said openings. v

10. In a furnace, the combination with a wall thereof, of a trough-shaped retort having its rear end upwardly inclined from the bottom to the top of the trough and having a horizontal shelf portion projecting rearwardly from said end abutting the wall aforesaid of said furnace, said shelf portion having a vertical opening for the passage of air, and a tuyere block having the rear wall thereof abutting the wall aforesaid of the furnace and resting upon the shelf portion of the retort, said block also having an in clined wall extending downwardly from the upper edges of the rear wall thereof and disposed in substantial alignment with the inclined rear end portion of said retort, the inclined wall of said tuyere being provided with an air outlet opening for discharging air longitudinally of the retort.

11. In a furnace bed, a hollow tuyere hav ing an air inlet opening at the bottom thereof and air outlet openings in certain of the side walls thereof, the top .of said tuyere being entirely closed and provided with an inwardly depressed portion adapted to retain heat-insulating materiahmeans for supplying air interiorly of said tuyere through said inlet opening, said depressed portion adapted to deflect the air to the said air outlet openings. i

In testimony whereof I afiix my signature.

WALTER F. 'rno'r'rnn. 

